tighten the screws on (one)
To exert excessive and coercive pressure, force, or threats of violence on one. The bank has really started tightening the screws on me ever since I began missing my mortgage payments. I'll send one of my strong men around to him tomorrow to tighten the screws on him. Then we'll see if he's still so sure he won't sign the contract.
tighten the screws
see under turn up the heat.
tighten (or turn) the screw (or screws)
exert strong pressure on someone. informal